We are studying the three dimensional structure of the tetramerization (T1) domain of the Kv3.1 voltage-gated potassium channel. This domain has been shown to be necessary and sufficient to form tetramers within subfamilies of voltage-gated potassium channels. We are currently searching for heavy atom derivatives and we anticipate solving the structure by multiple isomorphous replacement (MIR). The three-dimensional structure of this protein domain will provide a model to understand the structural basis of tetramerization of the Kv3(Shaw) subfamily of voltage-gated potassium channels. Other members of the lab are currently working on the structures of the corresponding T1 domains of the Kv1(Shaker) and Kv4(Shal) subfamilies. Combining what is learned from these structures will help us understand the molecular determinants of voltage-gated potassium channel tetramerization within subfamilies.